I'm still debating this. I have some parts to work with from a Ford LGT. But, after plowing with this tractor again, I am leery. At times, I had to 'ride the left fender' for traction. I don't have the tires loaded as yet, just the 75# weights. With a foot pedal for travel, I would have to stay in the seat.
My original idea came from trying to adjust the existing linkage to get maximum speed both fwd & rev. Not an easy task. Plus, the lever will not stay put, even after adjusting it so it is hard to move. The FF linkage is fairly simple, yet hard to adjust. & I have found nothing to tell you how to adjust it, all trial & error.
Right now, on the #2 FF, I have good forward speed, but very slow in reverse. I need to look at both tractors and see what I have different on this one. A piece of the linkage is just below a frame cross member, thus limiting the travel.
I'll see if I can get a pic of the parts page to show what I up against here. I may try to get some pics, but most have to be taken from under the tractor and not sure if you could see anything.
Here's the parts pic:
I marked the linkage parts with a red dot, hope it shows.